Asphalt-based roofing materials, such as roofing shingles, roll roofing and commercial roofing, are installed on the roofs of buildings to provide protection from the elements and to give the roof an aesthetically pleasing look. Typically, the roofing material is constructed of a substrate, such as a glass fiber mat or an organic felt, an asphalt coating on the substrate, and a protective and/or decorative surface layer of granules of stone, mineral, sand or other particulate material embedded in the tacky asphalt coating.
Roofing materials are expected to perform and maintain their appearance over time and in various conditions. The American Society of Testing Materials (ASTM) and Underwriters Laboratories (UL) have developed specifications, testing, and ratings for various properties of roof shingles, such as fire resistant, impact resistance, and wind resistance. Shingle manufacturers desire to provide roofing materials that meet or exceed the various standards, such as the UL 790, class A rating for fire resistance. To help achieve satisfactory performance regarding fire resistance, it is known to add fire resistant materials to roofing shingles and other roofing materials.